Bitumen outbreak detection system

ABSTRACT

A method for removing insoluble contaminants from a heat exchange system is disclosed. The method may be a single-pass system or a system incorporating a plurality of apparatuses in parallel. The method measures the pressure drop across a filter and purges contaminants based on the measured pressure drop. The method is particularly applicable to detecting and removing bitumen from a heat exchange system.

FIELD OF THE INVENTION

The invention is related to a method of and system for detecting a contaminant in a semi-closed loop heat exchange system. More specifically, the invention is related to a method of and system for detecting insoluble hydrocarbon contamination in a heat exchange system of a refinery. Even more specifically, the insoluble hydrocarbon is bitumen.

BACKGROUND

Of particular concern is contamination of the heat exchange fluid of a bitumen refinery. Bitumen is a viscous substance that is difficult to process unless heated to temperatures greater than 900° F. The equipment surfaces of a bitumen processing plant are typically heated with steam, giving the bitumen ample opportunity to leak into the heat exchange system. A bitumen outbreak is characterized as the release of an amount of bitumen into an aqueous stream that could affect the quality and usefulness of the aqueous stream, affect the environment, or could impinge the operation of a downstream process. The bitumen outbreak may originate from various sources, including but not limited to, process equipment, a tank, a pipeline, an oil spill, or the like. It is important to prevent bitumen and other insoluble contaminants from entering a heat exchange system that is associated with a bitumen processing plant, or any other chemical processing plant.

Accordingly, there is a need for a device and method of detecting and preventing insoluble contaminants from entering a heat exchange system. Desirably, the method would detect and prevent bitumen from entering the heat exchange system. More desirably, the method would be simple to implement and allow for continuous detection and prevention.

SUMMARY OF THE INVENTION

The invention is directed toward a method of detecting and removing a contaminant from a heat exchange system. The heat exchange system is comprised of a heat exchange fluid. The method comprises the steps of providing a plumbed apparatus that is operably connected to the heat exchange system, the plumbed apparatus comprises a filter and a differential pressure transducer; passing the heat exchange fluid through the filter; measuring the differential pressure across the filter; comparing the measured differential pressure to a setpoint; preventing the heat exchange fluid from passing through the filter when the measured differential pressure is greater than the setpoint; purging the filter with a purge fluid during the preventing; and optionally s repeating the passing, the measuring, the comparing, the preventing, and the purging steps. The differential pressure transducer is operably plumbed so that a differential pressure is measured across the filter.

The invention is alternately directed toward a method of detecting and removing a contaminant from a heat exchange system, with the heat exchange system again comprised of a heat exchange fluid. The method comprises the steps of providing a first plumbed apparatus and a second plumbed apparatus, with each apparatus operably connected in parallel to the heat exchange system, and each plumbed apparatus comprised of a filter and a pressure transducer, the pressure transducer operably plumbed to measure the pressure across each filter; first passing the heat exchange fluid through the first filter; first measuring the first differential pressure across the first filter; first comparing the measured first differential pressure to a first setpoint; first preventing the heat exchange fluid from passing through the first filter when the measured first differential pressure is greater than the first setpoint; first purging the first filter with a purge fluid during the first preventing; second passing the heat exchange fluid through the second filter; second measuring the second differential pressure across the second filter; second comparing the measured second differential pressure to a second setpoint; second preventing the heat exchange fluid from passing through the second filter when the measured second differential pressure is greater than the second setpoint; second purging the second filter with a purge fluid during the second preventing; and optionally repeating the steps from the first passing through the second purging.

For all embodiments of the invention, the contaminant is, for all practical purposes, insoluble in water. The contaminant may be bitumen.

These and other features and advantages of the present invention will he apparent from the following detailed description, in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:

FIG. 1 is a schematic drawing of two embodiments of the invention, wherein the entire schematic represents an embodiment and either the “A” Circuit individually or the “B” Circuit individually represents an additional embodiment.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

It should be further understood that the title of this section of this specification, namely, “Detailed Description of the Invention,” relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.

The invention at hand can be used to detect bitumen and other insoluble hydrocarbons in water streams like, but not limited to, return condensate, produced water, cooling water, boiler feed water, raw and river water. A preferred embodiment of the invention involves continuous detection and removal of bitumen by implementing at least two apparatuses that are virtually identical and that are operably plumbed in parallel to the heat exchange system. The apparatuses may be operably connected to a controller such as 3D TRASAR technology, available from Nalco Company, 1601 West Diehl Road, Naperville, Ill. 60563, or may be a stand-alone unit with its own electronic controller.

In an embodiment, the invention is a method of detecting and removing bitumen in a heat exchange system of a bitumen processing plant. The heat exchange system is comprised of a heat exchange fluid. The method comprises the steps of providing a plumbed apparatus that is operably connected to the heat exchange system, the plumbed apparatus comprises a filter and a differential pressure transducer; passing the heat exchange fluid through the filter; measuring the differential pressure across the filter; comparing the measured differential pressure to a setpoint; preventing the heat exchange fluid from passing through the filter when the measured differential pressure is greater than the setpoint; purging the filler during the preventing; and optionally repeating the passing, the measuring, the comparing, the preventing, and the purging steps. The differential pressure transducer is operably plumbed so that a differential pressure is measured across the filter.

As illustrated in the “A” Circuit of FIG. 1, the apparatus that may carry out the aforementioned method may be comprised of several pieces of equipment including a filter F1A, a pressure transducer T1A, several valves V1A, V2A, V3A, and V4A, and optionally a pressure regulator. The apparatus is arranged such that the pieces of equipment are operably plumbed to a heat exchange system that is comprised of a heat exchange fluid. In a preferred embodiment, the apparatus is plumbed to the condensate return line of a boiler system.

As illustrated in the “A” Circuit of FIG. 1, a heat exchange fluid flows through a valve V1A when valve V1A is open. When valve V1A is in the open position, so too is valve V2A, and valve V3A and valve V4A are in the closed position. The heat exchange fluid passes through fitter F1A, through valve V2A, and then returns to the heat exchange system. As the heat exchange fluid passes through valve V1A, filter F1A, and valve V2A, the differential pressure is measured across filter F1A by differential pressure transducer T1A, which is operably plumbed to the apparatus to do so. The differential pressure transducer T1A relays the measured differential pressure to an electronic control system (not shown), which compares the measured differential pressure to a setpoint. When the setpoint is reached or exceeded, the controller triggers valve V1A and valve V2A to close, and valve V3A and valve V4A to open, allowing a purge fluid to pass through filter F1A. The purge may last for a set period of time or until a another setpoint of differential pressure is reached. Once the purge cycle is complete, the valves may open and close as necessary to restart the method.

In a particularly preferred embodiment, the invention is a method of detecting and removing bitumen in a heat exchange system, with the heat exchange system again comprised of a heat exchange fluid. The method comprises the steps of providing a first plumbed apparatus and a second plumbed apparatus, with each apparatus operably connected in parallel to the heat exchange system, and each plumbed apparatus comprised of a filter and a pressure transducer, the pressure transducer operably plumbed to measure the pressure across each filter; first passing the heat exchange fluid through the first filter; first measuring the first differential pressure across the first filter; first comparing the measured first differential pressure to a first setpoint; first preventing the heat exchange fluid from passing through the first filter when the measured first differential pressure is greater than the first setpoint; first purging the first filter during the first preventing; second passing the heat exchange fluid through the second filter; second measuring the second differential pressure across the second filter; second comparing the measured second differential pressure to a second setpoint; second preventing the heat exchange fluid from passing through the second filter when the measured second differential pressure is greater than the second setpoint; second purging the second filter during the second preventing; and optionally repeating the steps from the first passing through the second purging.

As illustrated in FIG. 1 in its entirety, the method is carried out in the same manner as described above, with the key difference being that, while the “A” Circuit is in the purging step, the “B” Circuit is actively allowing the heat exchange fluid to pass through valves V1B and V2B along with through filter F1B. Valves V3B and V4B are in the closed position. Once differential pressure transducer T1B measures a differential pressure across filter F1B that is equal to or greater than the setpoint, the appropriate valves will open and close so as to divert the heat exchange fluid from passing through the “B” Circuit and back to the “A” Circuit. A person of skill in the art will readily recognize that the purge step again may be timed, may depend on a differential pressure measurement, or may continue for a period of time less than or equal to the alternate differential pressure transducer measuring a differential pressure that is greater than or equal to the setpoint.

When present, the optional pressure regulator may be manually or electronically controlled. In a preferred embodiment, the purge fluid is comprised of a compressed gas, which is more preferably compressed air. In another embodiment, the purge fluid is a liquid. The liquid may be a liquid cleaner from a clean-in-place system.

In an embodiment, the filters F1A and F2A are comprised of filter elements. The filter elements may be removable so as to be replaced from time to time, or depending on cost and convenience, the entire filter assembly (housing+element) may be replaceable. For this disclosure, the terms “filter” and “filter assembly” are interchangeable. The filter elements should be selected based on type, nominal pore size, and pressure drop, so as to prevent the proper insoluble contaminant from passing through. The characteristics of the insoluble contaminant(s), along with temperature, pressure, and flow rate of the aqueous fluid, are also important considerations when selecting a filter element. An increase in the measured pressure drop across the filter indicates that contaminants are accumulating on the fitter element. One of skill in the art will readily recognize that more than one setpoint can be programmed into such a control scheme, and that any number of setpoints can trigger alarms or control action.

In an embodiment, valves V3A, V4A, V3B, and V4B are solenoid valves.

In an embodiment, valves V1A, V2A, V1B and V2B are motorized valves.

In an embodiment, valves V3A and V4A will be in the closed position whenever valves V1A and V2A are in the open position; and also valves V3B and V4B will he closed whenever valves V1B and V2B are open.

In an embodiment, valves V1B and V2B will he closed when valves V1A and V2A are open, and vice versa.

In a particularly preferred embodiment, the invention detects and removes bitumen from a heat exchange system. For such an embodiment, a filter may be comprised of a Swagelok® Tee-Type Filter Housing (TF Series) and a sintered 316 Stainless Steel filter element, the element having perforated holes with diameters of 60 μm. An illustration of an embodiment of the filter assembly can he found at the Swagelok website (www.swagelok.com), with a person having skill in the art recognizing that the filter assembly may prefer a different shape depending on the application at hand. The differential pressure setpoints are determined based on the differential pressure rating of the filter element, as well as process standards, operational parameters, and target ranges. Such a setpoint determination would not require undue experimentation for one having skill in the art. A person of skill in the art will recognize that, as it relates to comparing a measured value to a setpoint, the term “greater than” should be interpreted to include “greater than or equal to” the setpoint.

All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.

In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.

From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the illustrated specific embodiments or examples is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. 

We claim:
 1. A method of detecting and removing a contaminant from a heat exchange system, the heat exchange system comprised of a heat exchange fluid, the method comprising the following steps: providing a plumbed apparatus, the plumbed apparatus operably connected to the heat exchange system, the plumbed apparatus comprising a filter and a differential pressure transducer, the differential pressure transducer operably plumbed so that a differential pressure is measured across the filter; passing the heat exchange fluid through the filter; measuring the differential pressure across the filter; comparing the measured differential pressure to a setpoint; preventing the heat exchange fluid from passing through the filter when the measured differential pressure is greater than the setpoint; purging the filter with a purge fluid during the preventing; and optionally repeating the passing, the measuring, the comparing, the preventing, and the purging.
 2. The method of claim 1, wherein the contaminant comprises bitumen.
 3. The method of claim 2, wherein the heat exchange fluid comprises water.
 4. The method of claim 3, wherein the filter comprises a 60 μm filter element.
 5. The method of claim 4, wherein the purge fluid is compressed air.
 6. The method of claim 4, wherein the purge fluid is a cleaning liquid.
 7. A method of detecting and removing bitumen in a heat exchange system, the heat exchange system comprised of a heat exchange fluid, the method comprising the following steps: providing a first plumbed apparatus and a second plumbed apparatus, the first plumbed apparatus and the second plumbed apparatus operably connected in parallel to the heat exchange system, the first plumbed apparatus comprising a first filter and a first differential pressure transducer, the first differential pressure transducer operably plumbed so that a first differential pressure is measured across the first filter, and the second plumbed apparatus comprising a second filter and a second differential pressure transducer, the second differential pressure transducer operably plumbed so that a second differential pressure is measured across the second filter; first passing the heat exchange fluid through the first filter; first measuring the first differential pressure across the first filter; first comparing the measured first differential pressure to a first setpoint; first preventing the beat exchange fluid from passing through the first filter when the measured first differential pressure is greater than the first setpoint; first purging the first filter during the first preventing; second passing the heat exchange fluid through the second filter; second measuring the second differential pressure across the second filter; second comparing the measured second differential pressure to a second setpoint; second preventing the heat exchange fluid from passing through the second filter when the measured second differential pressure is greater than the second setpoint; second purging the second filter during the second preventing; and optionally repeating the steps from the first passing through the second purging.
 8. The method of claim 7, wherein the contaminant comprises bitumen.
 9. The method of claim 8, wherein the heat exchange fluid comprises water.
 10. The method of claim 9, wherein the filter comprises a 60 μm filter element.
 11. The method of claim 10, wherein the purge fluid is compressed air.
 12. The method of claim 10, wherein the purge fluid is a cleaning liquid. 